Collector or power take-off plug for bus bar duct systems



Sept. 23, 1952 H. J. HAMMERLY EIAL 2,611,801

- COLLECTOR OR POWER TAKE-OFF PLUG FOR BUS BAR DUCT SYSTEMS 3 Sheets-Sheet 1 Filed Feb. 24, 1949 INVENTORS #501144 J 54mm? BY (756/1 5 70 670 A rm 2/1/51 P 23, 1952 H. J. HAMMERLY ETAL 2,611,801

COLLECTOR OR POWER TAKE-OFF PLUG FOR BUS BAR DUCT SYSTEMS Filed Feb. 24, 1949 3 Sheets-Sheet 2 46 E i 1 v45 i9 EVA 0A 0 A 5/91 QMO/VE Sept. 23, 1952 H. J. HAMMERLY ETAL COLLECTOR 'OR POWER TAKE-OFF PLUG FOR BUS BAR DUCT SYSTEMS Filed Feb. 24, 1949 5 Sheets-Sheet 3 I lirl.\

" The system to which Patented Sept. 23, 1952 COLLECTOR OR POWER TAKE-OFF PLUG FOR BUS BAR DUCT SYSTEMS Herman J. Hammerly, Cecil B. Turton, and

Rynold A. Salomone, Plainville, Conn., assignors, by mesne assignments, to General Electric Company, a corporation of New York Application February 24, 1949, Serial No. 78,102

8 Claims.

This invention relates particularly to a duct system having enclosed bus bars and an open slot which provides for access to the bus bars.

The main object is to provide a simple and effective form of plug-in device which can be readily inserted at any point and securely held in the duct and yet easily removed.

It is shown as applied to a two-pole system and a three-pole system but many features are applicable to a four-pole system.

Another object is to construct a plug which is adapted to be adjusted for alternative use in either side of a polarized system and thus avoid sectionalizing the system.

Another object is to provide a strain relief which serves as means for connecting the plug to the duct.

The details of the improvements will be understood from the following specification and drawings.

Fig. 1 is a view of the end of a duct with three bus bars and showing a collector in place.

Fig. 2 is a perspective view of the collector for a two-pole system.

Fig. 3 is a sectional view taken on the plane of the line 33 of Fig. 1.

Fig. 4 is a bottom plan view of the body of the collector of Figs. 1 and 3 and showing the arm of the yoke in section.

Fig. 5 is a perspective view of a fragment of the body of the collector with a stop detailed.

Fig. 6 is an enlarged sectional view of a part of the collector plug, the section being taken on theplane of the line 6-6 of Fig. 2.

Fig. 7 is an enlarged view of the inside of one half of the end of the collector.

Fig. 8 is a face view of a three-pole plug as applied to a duct and showing a part ofthe 13-43 of Fi 9.

Fig. 14 is a view taken on the plane of the line l4l4 of Fig. 9.

Fig. 15 is a view taken on the'plane of the line l5-'-I5 of Fig. 9.

" Fig. 16 is a sectional view taken on the plane of the line Iii-l6 of Fig. 9.

Fig. 17 is a perspective view ofone-half of the yoke of Fig. 8. p

the invention is applied is described and claimed in a copending application Serial No. 73,570, filed by Herman J. Hammerly on January 29, 1949 and. assigned tozthe same assignee as this application. This bus .bar duct system has a sheet metal duct l0 containing bus bars such as Hand I2 which are supported at intervals by insulators [3 which are mounted in the duct. The lower face or side of theduct has a slot between two flanges l4, l4 and the plug is inserted between these flanges so that its contacts engage the center bus bar l2 and one: or the other side bus bars. 1

The plug for a two-pole system has a basei l5 and a central relatively narrow extension 16 and is formed of two parts of molded insulation connected by screws or rivets I1 and I8. The extension l6 has a width somewhat smaller than the width of the slot in the duct so that the extension can be inserted freely through the slot into the duct. 1 l v Contact I9 is supported at the end of the extension and adapted to engage the center bus bar [2 when the plug is inserted. This contact is slidable in the end of the plug and backed by a spring 20 and cup 2| which rests on the end of the conductor 22 which in turn rests on the end of partition 23. The lugs 24 limit the "outward thrust of the contact [9. The lower end-of the contact strip 22 is fixed to the terminal block 21 which is seated in a recess between the two parts of the plug. At the end of the plug we provide flanges l6 alongside of the end contact so as to guard against shorting the end contact.

The other contact 26 of the plug is located in one side of the plug extension, projects through an opening in it and is separated from contact strip 22 by partition 23. i

The lower end of contact strip 26 is fixed to the terminal block 25 which is seated in a recess between the two parts of the plug.

The base l5 may be provided with passages 28 and 29 to receive conductor wire ends to be clamped to terminals Hand 21 by set screws 30 and 3|. The base also has slots 32 and 33120 receive the terminal blades of an attachment plug 34 on the end of a cable 35 so thatthe blades can engage the bowed parts of contact strips 22 and 26 adjacent the terminals 25 and 21.

A spring yoke is formed of two arms 36 connected by screws 31 and 38 for clamping the yoke to the cable 35. These arms are resilient. The yoke is preferably grounded at 39.

The upper ends of the arms 36 embracefthje base and are bent at right angles to projectover the ends of the base l5 and spread outwardlyby 3 their resiliency. Outward spreading of the arms is limited by the shoulder projections 40 and 41 on the base and by the cross bars 42 and 43 of the arms of the yoke.

The inner ends of the arms are provided with hooks and 'dfiwhich-are adapted to be'retracted by compressing the sides of the arms until the hooks extend into the recesses 46 and 41 so that the extension of the plug can be inserted between the flanges H, M and into the .duct. When the plug is fully inserted, pressure on .theyoke isreleased so that the hooks can interlock with the edges of the flanges and thus retain 'the'plug. in the duct. The yoke thus servesnot only tasa strain relief but supports the plug'in the duct.

In this system the duct i is symmetrical as thus described. The plug and'duct may be used as described. In order however to avoid the necessity of sectionalizing the system so as to balance the load on the two branches, the duct is "provided with an externally projecting flange :50 -r-unningiits :entire length and constituting :an -ex tension-oftheflange Tl lt'o form awiderfiange 50, J4, FandSthe plug is :so designed :as toensure that izzit mansbe inserted :for'its contact '28 .to :-engage iitheiright orcleftfbus bar according to:a predeter- :m'ined-plan.

This is effected by: providlngthe base of the IDlIlg-Wifih .undercutngrooves 15-! :andSZ adjacent the shoulders 49- and 41 respectively into one :of "which a 'stop '53 may be insertedandextends -upward along the inner side of the'adjacentishoul- ':der. :Suchxa stop :limits the space between the stop fand the zadjacent side "of the :extension [6 and the'plug .can '1on1y be inserted into the. duct --with the contact side of Ithe ,plug facing toward the otherfiside of the duct. With'the stopin- -sertedat the right as -shown. in Fig. 1* opposite the contact-26, the ;plug .can only be .insertedso that the contact will engage the left rhandibusbar. In other wordsth'e space between the stopi53'and the extension -I li while receivinga narrow flange [4; is-tooEnarrowtoreceive-.the-wider.-flanges50,4 4, although the space betweeneach shoulder 48 or ll-and the extensionrlG iswide enough toreceive the wider .-fiange. By insertingthe' stop in the -samesideof the plug as the contact,.-.-the plug :can-only-be inserted so that the-contactwillen- :gage the-righthandrbus bar. By'adjustingthe .gplugs; it is therefore (possible :to arrange to: draw .-0ne.ha1f.the load from one branch and theother -:half from the other 'branch.

In- -Figs.=8 to-l'i, inclusive, the inventionis shown-as applied to the three-pole-plug:or-colhector-60 for use inthesame duct as the two- :pole-plugwith-bus-bars l l, I l1 and t2 supported by insulators l3 and having iii-turned flanges-i4, hand an external flange. 50 alongone edge.

.In. this case, the plug .body .-is :formed of four parts GI, 62, GS andLEA-of molded-insulationheld etogether by screws or. rivets 65 and- 65. and there are three contacts 61.158 and B9. These contacts and terminalsare mounted in recesses between 'the respectiveparts. Contact .68 is. carried by a spring strip lll'whichis anchored to the terminal "blockllin the base of the plug. Strip 10 is. biased .to'project the contact from theplug so that when "theplugiis inserted in the duct the contact will press against one of the bus bars II. The base ofithe plug has an openingiil leading to'the' block H which is provided with aset screw 13 for .connection'with a branch conductor wire. Part-52 has a rec'esslll and groovel5 to accommodate one half "of the block TI .and the attached strip "IllandeontactEB. Part- 6! has a corresponding 4 recess and groove for the other half of the terminal and contact member. Parts S5 and 63 have identical recesses and grooves to house contact 67 and its terminal H.

5 The center contact 69 is similarly housed in recesses and grooves between the parts -62 and 63 of 'thelplugas shown in Figs. 14 and 15. The contact 69 is pressed outwardly by spring 1'! which abuts against the end 18 of conductor strip 18 110 which rests on the partition. The outward move- .mentof the contact is limited by the lugs 80 in the plug'and the contact is guarded by flanges 8|. The strip.-l8.is:anchored to a terminal block 82.in..the plug recess 83 which receives the end oi-abranch conductor wire through the opening 84' to be heldby a set screw 85.

.The three-pole. plug has projecting shoulders 86 and 8? with grooves 88 and 89 symmetrically spaced. from the sides of the plug for receiving a polarizing stop 80 as ;previously described with :respect. to :the TtWO- POIB plug.

The yoke for. clam-ping tozthe cable and to the duct isalsosimilar to that-for the two-pole plug. .Each .half .of the yoke. asshownin Fig. .l'lthas a frame with side arms-9| .to embrace the :sides of the base of the plug, flanges e2 terminating in hooks 93 forrengagingthe flanges M, 1420f the duct and -a clamp. screw -94 for drawing the two parts together andclampthe cable. The shoulders 86 and 8? of .the plug rbase. extend through theopenings 95 each in-the :upper-end and lateral portion of .one :armAJ-l aandeconstitute stops for the .end .wall. formed .by the cross barffifi. Moreover as shown in Fig. 8,.andalso in,Figs. l,.-2,: and 5,. theshoulders includeportions projecting laterally. outward from .theopposite sides of. the. base so that the lower or inner walls of theslots-SE engage .the lower laterally projecting endsof the shoulderstltand Withereby tosecure. thecollector plug 68 in the duct. As indicated Yin-Figs. l and. 2, .theshoulders All and Al extend through similar openingsinrthe. arms .36 and-are engaged .by the lower walls .of :theopenings to.secu-rethe plug in the duct.

45 Thesides of the yokecar.e.also preferably ;pro vided with outwardly extending :lugs 9:1 .to :form .fingengrips to said :in compressing the yoke in order. to. apply the yoke rand-plug-to theduct. One lug has an opening 93 to-allowionpassage :of .a screw driver for roperating the. set screw 85 for securing the conductor torthe .center zcontact terminal.

Weclaim:

1. A plug-in collector ior .a busiibar 'duct system comprising aninsulating body .havingan end contact for engagingacentralbus :barina duct and-acontactat one side .of the bodyifor engaging a bus bar at oneside :of :such duct, a cable having conductors connected-to said-contacts, a yoke secured to .saidz-cable .and' having outwardlyspringing arms embracing said insulating body and terminating in outwardly opening hooks forengaging.intunedespaced apart flanges of such a duct when insertedtherein.

.2...A.plugeincollector. for a bus bar duct-system comprising an insulating body havingacen- .tral .extension. and. havingam end contact f onengaging a central bus bar in a duct and a. contact at oneside .ofcthe-body. for engagingia bus bar at one side of such duct, a cable :havingconductors. connected to.=-said.contacts,..a yoke ,secured to said cable and havingmutwardly springing arms embracingsaid insulating.bodyand terminating in outwardly opening hooks-. for-engaging intunedspacedapartflangesiof sucha-duct when inserted therein, and a pair of shoulders on said -'their ends through which said shoulders extend respectively so that said shoulders are engaged by the end walls of said apertures to limit the separation of said ends of said arms.

3. A branch collector plug for attachment to a v duct having inturnedflanges at one face with an' 7 open slot between them and having bus bars within the duct and accessible through said slot,

said collector plug comprising an insulating base having an extension extending perpendicularly from its central portion and shoulders projecting from the edges of the base and parallel with said extension, contacts carried by said extension for engagement with the bus bars when inserted shoulders and terminating in an outwardly turned hook lying between said shoulder and said extension for interlocking withthe adjacent flange of the duct when the collector plug is inserted into the duct.

4." A branch collector plug for attachmentto a duct having in-turned flanges forming a side wall with an open slot between them and having bus bars within the duct accessible through the slot, said collector plug comprising an insulating base, a relatively 'narrow extension on said base extending centrally from said base having a width between opposite sides somewhat less than the width of the slot in the duct so that said extension can be readily inserted into the slot, a pair of shoulders on said base on opposite sides of said extension projecting laterally from opposite sides of said base, a plurality of contacts mounted on said extension for engagement with bus bars in the duct, a cable having conductors connected to said contacts and extending from saidbase, a yoke having two resilient arms embracing said base, means clamping the lower ends of said arms on said cable so that the upper ends of said arms are biased apart, each said arm being provided with an aperture in its outer end through which one of said shoulders extends so that said shoulders are engaged by the inner walls of said apertures respectively, and hooks on the ends of said arms for engaging the flanges of the duct thereby to secure said plug in the duct.

5. A branch collector plug for attachment to a duct having in-turned flanges forming a side wall with an open slot between them and having bus bars within the duct accessible through the slot, said collector plug comprising an insulating base, a relatively narrow extension on said base extending centrally from said base having a width between opposite sides somewhat less than the width of the slot in the duct so that said extension can be readily inserted into the slot, a pair of shoulders on said base on opposite sides of said extension extending each from said base in parallel spaced relation with the sides of said extension, a pair of shoulder portions projecting laterally from opposite sides of said base, a plurality of contacts mounted on said extension for engagement with bus bars in the duct, a cable having conductors connected to said contacts and extending from said base, a yoke having two resilient arms embracing the sides of said base and biased apart, means securing the opposite 6 ends of said arms on said cab1e,-each saidatrm having a portion extending laterally across the end of said base toward a side of said extension and each said arm being provided with an aperture in its end and lateral portion through'which one of said shoulders extends so that said shoulders are engaged by the end walls of said apertures to limit the separation of the ends of said arms and said laterally projecting portions are engaged by the opposite inner walls of said apertures respectively, and outwardly turned'hooks on the ends of said lateral portions, the opposite sides of said extension being provided with recesses to receive said hooks when the arms of said yoke are pressed together so that said hooks can be inserted after said extension in the slot in a duet, said arms when released springingoutward to engage said hooks with the flanges o! the duct, thereby to secure said plug'in the duct.

6. A branch collector plug for attachment to a duct having in-turned flanges forming a lower side wall with an open slot between them and having bus bars within the duct accessible through the slot, said collector plug comprising an insulating base, a relatively narrow extension on said base extending upward centrally from-said base having a width between opposite sides somewhat less than the width of the slot in the duct so that said extension can be readily inserted upward into the slot, a pair of shoulders on'said base on opposite sides of said extension extending upward from said base in parallel relation with the sides of said extension and spaced each from said extension to receive a flange on the duct, said shoulders projecting laterally iroin 'oppositesides of said-base, a plurality of contacts mounted on said extension for engagem'ent'withbus-bars in the duct, electric terminals in said base electrically connected to saidconta'cts, a cable having conductors connected "to said contacts and extending downward from said base, a yokeihaving two resilient upright arms embracing the sides of said base, means clamping th lower ends'of said arms on said cableso that the upper ends of said arms are biased apart, each said arm having an upper portion extending laterally across the upper end of said base toward said extension and each said arm being provided with an aperture in its upper end and lateral portion through which one of said shoulders extends both vertically and horizontally so that the upper ends of said shoulders are engaged by the end wall of said aperture to limit the separation of the upper ends of said arms and the lower laterally projecting ends of said shoulders are engaged by the lower walls of said apertures respectively, and outwardly turned hooks on the ends of said lateral portions, the opposite sides of said extension being provided with recesses to receive said hooks when the arms of said yoke are pressed together so that said hooks can be inserted after said extension in the slot in a duct, said arms when released springing outward to engage said hooks with the flanges of the duct, thereby to secure said plug in the duo 7. A branch collector plug for attachment to a duct having in-turned flanges forming a side wall with an open slot between them, one of said flanges being wider than the other, and having bus bars within the duct accessible through the slot, said collector plug comprising an insulating base, a relatively narrow extension on said base extending centrally from said base having a width between opposite sides somewhat less than the width of the slot in the duct so that said extenp 7 asiencan .he.-.r adilyoi sertedl nto the s ot. arai ,915 shoulders ,on;, ',sa .d. base. on opposite sides. of said extension extending from said basein paral- .lelzrelation" with the sides of said extension and having-inner sides spaced from said-extension ductrso, 13,8120 securesaid plug in theduct, said loase heing providedWith-an undercut groove adi;iacent;said-inner side ofeachof said shoulders, e;'ar rd.-ga -stop.member secured in oneof said grooves extending alfln the inner side of the adjacent shoulder and assuring the insertion 'of .the plug in the; slot in such .manner that the .narrower .fiange' on the -ductis between said step andsaid exten ion 8. 3 branch collector ,plug for attachment .to :aduct having ,in-turned flanges forming a side wall with an open slot-between them, one ofsaid flanges bein wider than the other, and having busbars-within theduct accessible through the slot, ;s aid collector :pl i comprising-an insulating ,loase, 5a I.relatii ely narrow extension on said base extending-centrally from said base, having a width between opposite-sides somewhat less than the width of the slot in the duct sothat said extension; can be readily inserted into the. slot, a pair or? shoulders on said base on opposite sides of said extension extendingfrom said base in parallel-relationrwiththe sides of said extension and spaced from-said extension to receive the wider ofthe two flanges-on the'duct, said shoulders in- -eluding portions projecting laterally from opposite .sides of said .base, ,alplurality of contacts mounted onsaid extension .for engagementmith bus bars. in the duct, a .cable. havingconductors connected to;:said. contacts .and extendin from said base, a yoke. having two resilientarmsembracing thesides of said base andbiased apart,

-means securing the lowerends of. saidcarmson saidcable, each-said arm having a portion extending laterallyacross the end of saidbasetoward a. side of said extension-and each said arm being provided with an aperturein its. endand lateral portion. through whichone of said shoulders extends so that said shoulders .are engaged by the end wall of said apertur to limitthe separation .of the. ends: .of .said arms and said-lateral shoulder portions are engagedbyth opposite lower walls oil-said apertures respectively, and outwardly .tumedhooks .onthe ends .01... said" lat- .eralarm portions, the opposite sides .ofssaid extension being provided with recesses to :receive said hooks :whenthe arms of said -yoke.=are

pressed togetherso that said hooks .cantbe inserted, after said. extension infthe-slot in a;duct, said arms .when released springin outward to engage saidhookswi-th the flanges .of thepduct, thereby to securesaid plug inthe duct-,said-base being provided withan undercut groove adjacent the inner side of each .of. said. shoulders. and a stop member secured in one of saidgrooves extending along the .inner side of the adjacent shoulder .for assuring )the? insertion of the plug in the slot in such manner that thenarrower flange on the ductis between said stop: and said extension.

j HERMAN J. HAMMERLY.

.CEClL B. .TURTON. RYNOLD. -A. SALOMONE.

REFERENCES CITED -The following references are .of recordin the file of this patent:

UNITED STATES PATENTS 

